Ballistic resistant laminate

Abstract

Improved ballistic resistant laminates have been developed by bonding alternating plies of fabric woven from glass or normally solid organic polymers and non-woven scrim prepreg impregnated with a heat curable resin. A preferred organic polymer is an aramid exemplified by Kevlar. A preferred heat curable resin is phenol-formaldehyde/polyvinyl butyral blend.

What is claimed is: 
     
       1. A ballistic resistant laminate comprising alternating plies of woven fabric bonded to alternating plies of non-woven scrim prepreg through a heat curable resin in said prepreg wherein said fabric is woven from filaments of glass or at least one normally solid organic polymer having: (a) a tensile modulus of at least about 20 g/denier;   (b) a tensile strength of at least about 400,000 psig; and   (c) an areal density at least about 0.5 lb/ft 2  and said scrim comprises filaments of natural or synthetic fibers impregnated with a heat curable resin.   
     
     
       2. Laminate claimed in claim 1 wherein the organic polymer is an aramid. 
     
     
       3. Laminate claimed in claim 2 wherein the aramid is poly(p-phenylene terephthalamide). 
     
     
       4. Laminate claimed in claim 1 wherein the fabric is woven from filaments of S-2 Glass fiber. 
     
     
       5. Laminate claimed in claim 1 wherein the heat curable resin is a phenol-formaldehyde/polyvinyl butyral resin. 
     
     
       6. Laminate claimed in claim 1 wherein the heat curable resin constitutes about 15-20% by weight of the organic polymer. 
     
     
       7. Laminate claimed in claim 1 wherein the heat curable resin constitutes about 20-25% by weight of the S-2 Glass fiber. 
     
     
       8. Laminate claimed in claim 1 wherein the cured resin slightly penetrates the interface between the woven fabric and the non-woven scrim. 
     
     
       9. Laminate claimed in claimed 1 wherein the organic polymer is a high modulus polyethylene. 
     
     
       10. Laminate claimed in claim 1 wherein the organic polymer is nylon. 
     
     
       11. Laminate claimed in claim 1 wherein the non-woven scrim is a polyethylene terephthalate. 
     
     
       12. Method of fabricating a ballistic resistant laminate which comprises: (1) assembling alternating plies of fabric woven from glass or a normally solid organic polymer and non-woven scrim prepreg impregnated with a heat curable resin and   (2) subjecting the assembly of (1) to conditions of heat and pressure sufficient to cure the resin and bond the alternating plies of woven fabric and non-woven scrim into an integral structure; wherein said polymer has:   (a) a tensile modulus of at least about 20 g/denier;   (b) a tensile strength of at least about 400,000 psig; and   (c) an areal density at least about 0.5 lb/ft 2  and said scrim comprises filaments of natural or synthetic fibers impregnated with a heat curable resin.   
     
     
       13. Method claimed in claim 12 wherein the assembly of step (1) is shaped into a formed article during curing step (2). 
     
     
       14. Method claimed in claim 13 wherein the formed article is a military helmet. 
     
     
       15. Method claimed in claim 13 wherein the formed article is a panel of armor. 
     
     
       16. Method claimed in claim 12 wherein the organic polymer is an aramid. 
     
     
       17. Method claimed in claim 16 wherein the aramid is poly(p-phenylene terephthalamide). 
     
     
       18. Method claimed in claim 12 wherein the fabric is woven from filaments of S-2 Glass fiber. 
     
     
       19. Method claimed in claim 12 wherein the heat curable resin is a phenol-formaldehyde/polyvinyl butyral resin. 
     
     
       20. Method claimed in claim 12 wherein the heat curable resin constitutes about 15-20% by weight of the organic polymer. 
     
     
       21. Method claimed in claim 12 wherein the heat curable resin constitutes about 20-25% by weight of the S-2 Glass fiber. 
     
     
       22. Method claimed in claim 12 wherein the non-woven scrim is a polyethylene terephthalate.